Hitachi EX300LC-1 Hydraulic Oil Selection (ISO 68 vs ISO 46)

Hi everyone

I recently purchased a Hitachi EX300LC-1 in reasonable condition for a small granite mining operation. The machine will be using an NPK hydraulic breaker for around 50-60% of its operating time. I am unsure about the viscosity of hydraulic oil which should be used in the excavator since the information I am receiving regarding this from different sources is conflicting. Any help or advice from esteemed members would be greatly appreciated (Apologies for the long post!)

Background

The previous owner had already filled up the tank with new ISO 68 oil before sale. Since he was a reseller, he was unsure what was being used in the machine before that. When I inquired about his choice of oil viscosity, he said thicker oil works better with the older machines and requires less frequent replacement. I have also asked two other local mechanics who regularly work with older EX models and both are adamant that ISO 68 is the correct choice. Infact they claimed they have never used anything less than an ISO 68 on the machines they have worked on in the past.

On the other hand, the local Hitachi dealer insists that ISO 46 is the correct choice and using a thicker oil will cause hydraulic pump cavitation and failure.

Doing some research online I found information regarding hydraulic oil ambient temperature ranges that was equally conflicting. Some sources said that ISO 46 ambient temperature range is -4°C to 21°C (+25° to +70°F) and ISO 68 ambient temperature range is +4°C to +32°C (+40° to +90°F). While other sources said ISO 46 is designed to work in ambient temperatures of -20°C to +35°C (-4° to +95°F).

Further information

a) The machine has twin axial piston pumps
b)The weather in winters (Nov-Feb) minimum is about -4°C (25°F) to a maximum of say 10°C (50°F)
c)The weather in the summers may be a minimum of 10°C (50°F) in the mornings with afternoons going up to 25°C (77°F) usually, but sometimes even up to 30°C (86°F)
d)The machine will be using a hydraulic breaker for around 50-60% of its total operating time

Query

1) Considering that summers are just around the corner, can I safely use the existing ISO 68 oil without any damage to the pumps and change it to an ISO 46 in about 6 - 7 months before winters?
2) Considering the conflicting temperature range information online would I then need to use a 68 in summers and a 46 in winters or can I then keep using the ISO 46 throughout the year.
3) Does the significant planned hydraulic breaker usage have any impact on the decision of oil viscosity being used? (possibly because it would further raise the operating temperature of the oil when being used)

Thank you!

In your climate the 46W would be my choice. When using the breaker I would consider changing the hydraulic oil more often. I don't know if the older hitachi's used zinc free oil or not. You need to find out what's needed and what brand was used when it got changed from the last owner. On some of the hydraulic pumps on the Hitachi/Deere machines the silver that is one of the metals used in some of the components reacts badly and causes the pump to fail prematurely. I would take an oil sample to test your oil to see where things are at especially running a breaker.

What year? The older machines can use 32 or 46

Don’t fuss about it. Let’s keep it real. That is an old beast. She will immediately start blowing hoses when you start hammering. The ISO68 will be distributed all over your mine.

Then, you can fill it with AW46. Have a few drums ready.

Thank you all for your valuable advice and comments.

I am finding it quite difficult to find best practices for these older models, even from the Hitachi dealers. I asked the pervious owner today about the oil viscosity being used in the machine before he acquired it. He wasn't sure and wasn't being too helpful, while maintaining that ISO 68 is the best choice.

This is a 1991 EX300LC-1. Does anyone know if the pumps for this model react badly to zinc in the hydraulic oil?

I was reading another thread (https://www.heavyequipmentforums.com/threads/wrong-hydraulic-oil-added-now-what.34141/) and comments from member Nige from 2013 suggest that using a zinc based hydraulic oil for the larger Hitachi's can be detrimental for the hydraulic pumps. Not sure if that is also true for such an old model?

The current starting temperature is around 8° to 10 °C which looks like it is within range for ISO 68. If I can be absolutely certain that zinc is not a problem, I might leave the ISO 68 in it for 400-500 hours and replace it with an ISO 46 thereafter.

Zinc is fine.

Per Hitachi it's ok on new ones as well.

It's a Hitachi. It needs ISO46 ashless (zinc-free) hydraulic oil. End of........
The Hitachi oil is called 46HN - https://www.hitachicm.com/global/en/products/parts-service/parts/hydraulic-oils/
All major oil companies will sell an ashless hydraulic oil alongside their regular hydraulic oils.

ISO68 in the UK climate is far too heavy. I wouldn't even contemplate using ISO68 in a tropical climate.

I can't comment on whether hydraulic oil containing zinc will be a major problem in your model. All I can say is that it would be catastrophic in a larger machine (EX1200 upwards). The upside as far as you are concerned is that spare parts for your machine will be a lot cheaper than they would be for an EX3600..!!

Understood thanks Nige!

I am more inclined towards immediately replacing the oil with an ashless 46.

Do you know the ambient temperature range for ISO 46? We may go up to 30° - 32° C in the summers and I am wondering if it will still be fine at those temperatures

Also, UK has more of a temperate climate, rather than tropical

On all the Hitachi equipment I came across the recommendation was 46HN no matter what the ambient temperature. For hotter climates there was often an auxiliary hydraulic system cooling package available to maintain hydraulic oil temps within the required limits which IIRC was up to a permitted max of something like 115 DegC.

We used 46HN (or commerical equivalents from Mobil, Shell, & Conoco Phillips) in Hitachi hydraulic systems in tropical climates with temperatures significantly above the ranges you mention so IMO it will work fine in your quoted temps. Our lows were probably never below 20 and highs were probably close to 40. None of our machines had the aux cooling package.

MKF1 said:

Thank you all for your valuable advice and comments.

I am finding it quite difficult to find best practices for these older models, even from the Hitachi dealers. I asked the pervious owner today about the oil viscosity being used in the machine before he acquired it. He wasn't sure and wasn't being too helpful, while maintaining that ISO 68 is the best choice.

This is a 1991 EX300LC-1. Does anyone know if the pumps for this model react badly to zinc in the hydraulic oil?

I was reading another thread (https://www.heavyequipmentforums.com/threads/wrong-hydraulic-oil-added-now-what.34141/) and comments from member Nige from 2013 suggest that using a zinc based hydraulic oil for the larger Hitachi's can be detrimental for the hydraulic pumps. Not sure if that is also true for such an old model?

The current starting temperature is around 8° to 10 °C which looks like it is within range for ISO 68. If I can be absolutely certain that zinc is not a problem, I might leave the ISO 68 in it for 400-500 hours and replace it with an ISO 46 thereafter.

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Hello,

He is Maintaining the stance on the 68 because that’s what he had and it was cheap. He didn’t want to spend $200 a pail for the good stuff.

Hitachi Deere didn’t switch to non-ZDDP anti-wear additive packages until mid to late 90’s. Tell me I’m wrong, but zinc free hydraulic oil wasn’t even available in 1991.

Nobody, in the workplace, especially the dealership network has any institutional knowledge about these machines. I was in my early twenties when that machine was put to work. Us ex-dealer techs are pushing 60. We don’t work on dash -1 machines because you have the only one left.

It’s great you are doing the research. That’s awesome. I would use AW46. Especially starting out. Until you get the bugs worked out.

Putting a 32 year-old machine into the worst severe duty cycle, running a hammer, is going to very eventful.

Another thought to throw into the mix regarding viscosity. If it was a Cat machine (and quite a few other brands as well) the preferred hydraulic oil would be an SAE 10W, which viscosity-wise sits somewhere between an ISO 25 and a 32. So compared to that, a 46-viscosity oil would be considered "heavy", and a 68 "somewhere close to gear oil".........

Thank you both for your advice. This is very helpful.

We will have a look to see if we can find a good 46 for the machine for immediate replacement.

I was initially more inclined towards leaving the 68 in there until the next oil change which with a breaker would be at around 600 hours. Cash outflow and disruption to operations being the primary considerations. But probably not worth taking the risk of causing any permanent damage to the pumps which would ultimately become even more expensive. The pumps are in very good condition.

Thanks again!

In 1991 we knew nothing of zinc free oil, use regular 46 and it will function fine. Back then, and even today many used tractor hydraulic oil. It's not recommended but when they have done it for 8-10,000 hours it's also hard to argue that it's bad for the machine.

excavator said:

In 1991 we knew nothing of zinc free oil, use regular 46 and it will function fine. Back then, and even today many used tractor hydraulic oil. It's not recommended but when they have done it for 8-10,000 hours it's also hard to argue that it's bad for the machine.

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The answer to that would be that back in 1991 we were using TO-2 specification oil in powertrains, now we use TO-4. It's called progress IMHO. Although you can still find people who swear by the snake oil they were using decades ago.

excavator said:

In 1991 we knew nothing of zinc free oil, use regular 46 and it will function fine. Back then, and even today many used tractor hydraulic oil. It's not recommended but when they have done it for 8-10,000 hours it's also hard to argue that it's bad for the machine.

Click to expand...

I took a commuter flight today and had time to contemplate life in the 90’s, Grunge, flannel and zinc free oil. I do recall a zinc free product from Mobile called EAH-224. It was vegetable based. It stained you, your clothes, paint and everything else, yellow. Smelled horrible. The USFS required it for contracts within the Tongass. Made hydraulic pumps wear out fast.